The present invention relates to an improved dispenser head structure for a garden watering sprinkler. The dispenser head is integrally combined with a base plate by ultrasonic welding method. The dispenser head is secured to the head portion of a sprinkler gun by a screw. The dispenser head is provided with a plurality of radially distributed full discharge openings on the periphery thereof. The dispenser head has a round board on which are equipped with 4 discharge outlets at the central area thereof. A ring area disposed adjacent to those peripherally located full discharge openings is provided with a plurality of bores. A round area is disposed at the center area circled by the 4 discharge outlets. There are a small C-shaped partition wall area and a large C-shaped partition wall area on the rear side of the round board, that are continually connected to the tubular extension of the 4 discharge outlets by vertical walls so that a closed area is defined at the center thereof. There are 6 inlet holes and 4 full discharge outlets on the base plate. The 6 inlet holes are registered with the 4 tubular extensions and the small and large C-shaped partition wall areas. Water can be filled up the closed area via the large C-shaped partition wall area and discharged via the multiple full discharge openings when the dispenser head is rotated to make the large C-shaped partition wall area selectively registered with a water discharge hole. Such a dispenser head permit a reverse flow of water externally jetted against the dispenser head to clean dirt accumulated in the dispenser head. The removed dirt can be brought out of dispenser head via the full discharge openings.
Referring to FIG. 1, the exploded components of the prior art comprises a sprinkler gun 10, a seal ring 14, a positioning pin 16, a screw 17, a dispenser head 20 and a base plate 30. The sprinkler gun 10 has a head portion 11 provided with an internally threaded post 12. Right above the internally threaded post 12 is disposed a water discharge hole 13 in which are disposed a number of axially defined ribs 131. A positioning hole 15 is placed at a distance under the water discharge hole 13. The dispenser head 20 is has a plurality of inwardly and radially tapered ribs 21 connected to a round board 22 full of discharge bores. Between every two ribs 21 is defined a full discharge opening 25. There are 6 variation discharge outlets 23 and 2 closed circular areas 24, as shown in FIG. 2. Each discharge outlet 23 has a backwardly defined tubular extension 26. There are 6 inlet holes 31, a finely netted water inlet hole 32, a key hole shaped cavity 33 disposed on the base plate 30 on the rear side of which are disposed 8 retaining recesses 34.
In assembly, as shown in FIG. 3, the base plate 30 and the dispenser head 20 are integrally fixed together by an ultrasonic welding method with the 6 inlet holes 31 of the base plate 30 registered with the 6 tubular extensions 26. The peripheral flange wall 35 is placed at a distance with the inner wall of the dispenser head 20. The positioning pin 16 is housed in the positioning hole 15 and a seal ring 14 is placed in the water discharge hole 13 of the head portion 11 of the sprinkler gun 10. The dispenser head 20 is secured to the head portion 11 of the sprinkler head 10 by a screw 17 which is engaged with the central hole of the dispenser head 20 and the base plate 30 and the internally threaded post 12. The inlet holes 31 of the base plate 30 are rotated into selective registration with the water discharge hole 13 and retained in place by the positioning pin 16 which is selectively registered with one of the retaining recesses 34.
When one of the inlet holes 31 of the base plate 30 is selectively registered with the water discharge hole 13, water can be discharged out of one of the variation discharge outlets 23. Alternatively, the finely netted water inlet hole 32 registered with the closed circular area 24 is engaged with the water discharge hole 13, water can be discharged via the bored ring area of the round board 22 of the dispenser head 20. As further shown in FIG. 4, when the water discharge hole 13 is placed in alignment with the key hole shaped cavity 33 of the base plate 30, water can be led into the space between the peripheral wall 35 and the inner wall of the dispenser head 20. Thereby water can be discharged out of the full discharge openings 25 among the ribs 21 of the dispenser head 20.
To clean accumulated dirt out of the garden watering sprinkler of the prior art, external water flow is jetted against the dispenser head 20 so that water can be led into the full discharge openings 25, all other variation discharge outlets 23 and all dirt is flushed into the inlet holes 31 of the base plate 30 and also the netted inlet hole 32. Finally, the removed dirt is brought into the sprinkler gun 10 and expelled out via the full discharge openings 25.
The prior dispenser head 20 has the following disadvantages in use:
1. When water is discharged out of the full discharge openings 25, the key hole shaped cavity 33 of the base plate 30 is registered with the water discharge hole 13 of the head portion 11 of the sprinkler gun 10. In that case, water is limited and easily concentrated in the full discharge openings at lower portion of the dispenser head 20. PA1 2. The externally jetted water flow is easily limited by the key hole shaped cavity 33 when dirt of the dispenser head 20 is to be cleaned, so it is relatively hard to get the dispenser head precisely and completely cleaned.